Glen Powell Says He Vomited After Watching 'Hidden Figures' Rough Cut

Glen Powell had a strong reaction to watching "Hidden Figures" the first time ... but, it wasn't exactly a happy one -- admitting he puked after leaving a rough cut of the film.

The actor appeared on the "Therapuss with Jake Shane" podcast this week and got real about starring in the hit 2016 biopic ... saying he totally blanched after watching an early screening.

GP -- who played real-life astronaut John Glenn in the movie -- says he watched the movie before the effects or music had been put in, a very bare-bones version ... and, he genuinely thought he ruined the movie.

Powell says he left the room feeling like he'd done a disservice to the memory of the real women who helped get America to the moon during the '60s -- while also tanking all his costars' hard work ... and, he got so overwhelmed he threw up into the bushes on the Fox lot.

Glen says the added aspects the first cut lacked ended up making the movie a whole lot better in the end ... so, he probably flipped out a bit too soon.

It seems he and his costars ultimately did just that ... "Hidden Figures" is a critical and commercial success -- racking up a 93% on Rotten Tomatoes while bringing in more than $230 million at the box office. It also earned three Oscars nods -- including Best Supporting Actress for Octavia Spencer.